It is known in practice to fasten the primary air channel of trucks to a driver's cab rear wall. The primary air channel is also denoted hereinafter as the air suction duct or primary air duct. For decoupling the air suction duct from the driver's cab in terms of vibration technology, said air suction duct is fastened to the driver's cab rear wall by means of rubber-metal buffers.
This is shown by way of example in FIG. 1 which shows a view in the direction of travel of the rear wall 2 of the driver's cab of a truck. The air suction duct is denoted by the reference numeral 1 and is fastened to the driver's cab rear wall at the four screw connection points 3. FIG. 2 shows a sectional view of the screw connection point 3 along the line A-A of FIG. 1. The two rubber-metal buffers 4 serve as resilient supports between the driver's cab rear wall 2 and the air suction duct 1. In this case the rubber-metal buffers 4 are initially screwed by means of a socket wrench and a defined torque into the rivet nut 5 integrated in the driver's cab rear wall 2. Subsequently, the air suction duct 1 is suspended on the rubber-metal buffers 4, and aligned and tightened by the same tool or a separate tool by one respective nut 9 comprising a washer 8.
In this known fastening method of the primary air channel 1 to the driver's cab rear wall 2, it has been additionally established that the rubber-metal buffers 4 twist once during the screwing procedure by up to 180 degrees about their longitudinal axis. After positioning the socket wrench the twisting is relaxed to ca. 45 degrees. The consequences of such twisting are a negative impact on the damping properties of the rubber-metal buffer 4 and a restriction of the service life of the rubber-metal buffer 4. Thus, it is an object of the present disclosure to provide an improved fastening device, the drawbacks of conventional techniques being able to be avoided thereby.